Post-stoke central pain syndrome is notoriously difficult to treat. The exact reason why some patients develop this debilitating condition is unclear. Current theories suggest that when the brain is deprived from sensory input originating from the body, a sensory “vacuum” is created in consciousness. This sensory vacuum is filled-in by the brain. Unfortunately in some patients, the brain replaces the missing sensation from the body with the perception of pain. Note the fMRI studies above. The red and blue highlights demonstrate the brain’s response to sensory stimulation of the feet. Normally stimulation of the right foot would produce increased activity in the left hemisphere of the brain. The image above left shows very little blue highlight in the left hemisphere as a result of sensory stimulation of the right foot, the sensory vacuum. After a course of treatment in our office, the follow-up fMRI continues to show the sensory vacuum in the left brain (above right), however the brain shows evidence of re-mapping. It shows that the right hemisphere is now (red highlights) taking over the lost function of the stroke-damaged left hemisphere. These fMRI changes post treatment correlated with clinical improvement in this patient and presumably are a result of this cortical re-mapping in response to targeted sensory stimulation. (return)